We built our house 17 years ago and paid extra for things like double-glazed windows and enhanced insulation over and above the standards required at that time.

Now technology has made heat-exchangers, turbines, solar panels etc more affordable I would take them on in a new-build without a second thought PROVIDED I could see the evidence of the benefit:
e.g. this "extra" will cost me £1000 now but reduce my average annual energy bill by £x amount, so after y years I'm ahead.

Too many people are running the risk of screwing it up by making false claims for their products, e.g. electric heaters that are more than 100% efficient just because they have a thermostat so don't run all the time!